The present invention relates to handpieces which utilize a stream of high pressure air to effect rotation of a tool bit received therein.
Air-driven handpieces are widely employed for effecting oscillation or rotation of a tool bit so as to perform a desired task, either upon a patient or upon a workpiece. Generally, such handpieces utilize a high pressure stream of air acting upon a rotatable or reciprocatable element connected to the tool receiving element to impart the desired motion to the tool bit.
Many of such handpieces utilize a turbine wheel upon which the air stream impinges to effect rotation thereof and thereby effect rotation of a spindle which carries the tool bit. Such handpieces are particularly advantageously used in dental laboratories wherein the tool bit comprises a bur or other abrading tool to facilitate hand shaping of a workpiece.
Among the problems encountered in the use of high speed turbine handpieces of this type are the noise resulting from the air discharge, a tendency for the handpiece to walk along the workpiece due to the angularity of air discharge and low torque at low air velocity.
It is an object of the present invention to provide a novel air powered handpiece to effect rotation of a tool bit, and which provides highly effective and long lived operation.
It is also an object to provide such a handpiece wherein the parts may be readily and relatively economically fabricated and assembled.
Another object is to provide such a handpiece which will operate over a range of velocities in the air feed stream to effect useful rotation of the tool bit mounted therein.